Are contraceptive candles very save?

And how often I must to use theirs, and are they had side effects?
As non hormonal candles against pregnancy as contraceptive contain of spermicide and additional substance as she is diluting in vagina of high temperature and spermicide substance activating and additional component effects,like lubricant. And in a few candles kinds having and additional functions as in a few containing nonaxynalon and in an other is chloride benzalconia and they are destroy for membrane spermatozoid, and his activity lowering ,thus and pregnancy not ability.
And this remedy effectively just on 80 cases and to the pregnancy leading as wrong this remedy using,thus you are needing right doing instructions,which you are finding on the box,and one stealth her as to enter candle before sex act, but needing a time,hat she will dilute,and a most effect she gives within 40 minutes and in repeat act use a new,and for her effecting as to and after sex as on hygienic toilet is not using a soap.
And they had not contraindications, just if you are could not endured theirs, and in regular use they are destroy vagina micro flora, but they are care of virus and a few other infections, but not save of sex diseases, and theirs smell is not good from a few kinds.